Ballistic armor is well known in the art as is herein detailed and described together with explanation why the prior art could be improved or in some essential features is different from the present invention.
U.S. Pat. No. 5,972,819 issued to Cohen reveals ceramic bodies in composite armor where the ceramic bodies end-face curvature is in a specific range of sizes relative to the diameter of the ceramic body.
U.S. Pat. No. 7,117,780 issued to Cohen reveals composite armor plate using a layer of pellets held by elastic material.
U.S. Pat. No. 6,860,186 issued to Cohen reveals a ceramic body in ballistic armor where the ceramic body is peg shaped with a head and a stem.
French patent No. 2526535 issued to Pequignot reveals ceramic elements embedded into a metallic plate and thermally stressed.
The Pequignot arrangement can not exploit the full potential of the metal to stress the ceramic elements since a major part of the embedding metal does not contribute to efficient confinement and stressing.
In European patent application No. 13631001 by Ravid et al, an arrangement of pellets is proposed wherein a belt member is adapted to provide inward radial compression to said pellets.
U.S. Pat. No. 6,826,996 issued to Strait reveals composite armor in a honeycomb structure with polygon openings and inserts in the openings. A method of manufacturing is revealed for filling the polygon openings with resin.
U.S. Pat. No. 5,361,678 issued to Roopchand reveals coated ceramic bodies in composite armor where the ceramic bodies are embedded in a metal matrix. In the international application No 2007048370 by Weber et al proposes a composite armor which comprises elongated rods arranged in parallel with each other.
U.S. Pat. No. 5,686,689 issued to Snedeker reveals lightweight composite armor in a matrix block with a planar back, intersecting ridges and fillets. In each cell there is an energy absorbing ceramic material.
U.S. Pat. No. 6,532,857 issued to Shih reveals a ceramic array armor confined with shock isolated ceramic tiles with rubber between the tiles and over the top of them. Polysulfide is used as an encapsulation component.
U.S. Pat. No. 6,332,390 issued to Lyons reveals ceramic tile armor with enhanced joint and edge protection using ceramic strips with adhesive.
The experimental results by Holmquist and Johnson (EDP Sciences 2003) show that pre-stressed ceramics does improve performance.
Yiwang Bao etal (materials letters December 2002) reported substantial enhancement in projectile penetration resistance in confined pre-stressed tiles. They also reported a 15 times enhancement of the impact resistance of a three dimensional pressed Alumina bar.
The writers further conclude that a three dimensional stressing of ceramic provides a higher enhancement in the impact resistance then a two dimensional stressing.
US statutory invention number H1434 reveals a method for assembling pressed ceramic tiles is suggested by compressing thermoplastic material into a cavity. The above prior art uses different methods to increase the impact absorption factor of armor by subjecting ceramic elements to pre-stress.
The methods that were known for achieving pre-stress in armor prior to the present invention were by compressing thermoplastic material into a cavity, a method which involves a weight penalty due to low ballistic efficiency of the thermoplastic material and thermal shrink fitting, a method which is limited by the adverse influence of high temperatures on the enclosure properties.
The present invention reveals an armor comprising confined and pre-stressed ceramic elements of novel kinds, formations and combinations, and a novel method of achieving lightweight and highly stressed ceramic armor and thus increases the impact absorption factor.
The present invention is characterized by the provision of one or more of the following; efficient arrangements of confined and pressed ceramic elements wherein the elements are pressed in three dimensions, efficient arrangements of pressed ceramic elements wherein pressure is applied to the strike face of the ceramic elements, confined and stressed ceramic elements by enclosures that are shaped like pressure vessels comprising cylindrical and dome shaped surfaces, the use of light weight efficient cylindrical and dome shaped pressurized enclosure segments enables to achieve a uniform high stress in the enclosure,
The present invention also provides an armor comprising an auxiliary layer disposed in front thereof at a determined distance wherein said layer comprises a confined and pre-stressed members arranged in a spacious pattern.
It is also the scope of the present invention to provide a steel and concrete pre-stressed member used for civil engineering structures as well as in armor and fortified structures that is light weight, blast and impact resistant and can better withstand earthquakes.